1. Field of the Invention
The invention relates to a vehicle control system that causes a host vehicle to travel on the basis of a relationship with another vehicle traveling near the host vehicle.
2. Description of Related Art
Conventional vehicle control systems of this type are disclosed in Japanese Patent Application Publication No. 2008-059094 (JP-A-2008-059094) and Japanese Patent Application Publication No. 63-098706 (JP-A-63-098706), for example. JP-A-2008-059094 discloses a technique relating to vehicle interval control in which a target speed and a target acceleration/deceleration of a certain vehicle in a vehicle group are set on the basis of a target speed and a target acceleration/deceleration of another vehicle in the vehicle group, the set target speed and target acceleration/deceleration are transmitted to the vehicle by communication, and the vehicle is subjected to travel control so that the speed and acceleration/deceleration of the vehicle match the target speed and target acceleration/deceleration. JP-A-63-098706, meanwhile, discloses a technique relating to vehicle interval control in which vehicle-to-vehicle communication is performed between at least two vehicles and travel control is performed on a host vehicle on the basis of a received target acceleration of the other vehicle.
Incidentally, a response delay may occur in a vehicle between a point at which a control command for attaining a control target value such as a target vehicle acceleration is issued and a point at which an actual output matches the control target value an actual output, depending on a control response characteristic of the actual output value relative to the control target value. Therefore, when the host vehicle is travel-controlled on the basis of the control target value of the other vehicle, it may be impossible to perform the travel control appropriately, depending on the control response characteristic relative to the control target value. In the vehicle interval control described above, for example, a target vehicle acceleration and a target vehicle speed of a following vehicle may deviate from desired control target values relative to an actual vehicle acceleration and an actual vehicle speed of a preceding vehicle, and as a result, an ability of the following vehicle to follow the preceding vehicle may deteriorate.